issues with binary files to VBO

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5 comments, last by og knuckles 8 years, 8 months ago

so I have been struggling with this problem for a while and have tried many different ways of doing it. Currently I am loading in a binary file that is in bytes and sending it to openGL however nothing is rendering.

this is how I have been creating the binary file


			binaryFloat x,y,z,w,u,v,normx,normy,normz;
			x.f = PD[i].x;
			y.f = PD[i].y;
			z.f = PD[i].z;
			w.f = PD[i].w;
			u.f = PD[i]._U;
			v.f = PD[i]._V;
			normx.f = PD[i].norm.X;
			normy.f = PD[i].norm.Y;
			normz.f = PD[i].norm.Z;

			fout << x.container[0] << x.container[1] << x.container[2] << x.container[3]
				<< y.container[0] << y.container[1] << y.container[2] << y.container[3]
				<< z.container[0] << z.container[1] << z.container[2] << z.container[3]
				<< w.container[0] << w.container[1] << w.container[2] << w.container[3]
				<< u.container[0] << u.container[1] << u.container[2] << u.container[3]
				<< v.container[0] << v.container[1] << v.container[2] << v.container[3]
				<< normx.container[0] << normx.container[1] << normx.container[2] << normx.container[3]
				<< normy.container[0] << normy.container[1] << normy.container[2] << normy.container[3]
				<< normz.container[0] << normz.container[1] << normz.container[2] << normz.container[3];

binaryFloat is a union containing a float and a char[sizeof(float)]. PD is a packedData vector that contains preparsed data.

Here is where I load it up in my engine:


	std::ifstream objFile(filename, std::ios::binary);

	if (objFile.is_open())
	{
		unsigned int length;
		char  *data;
		objFile.seekg(0, std::ios::end);
		length = objFile.tellg();
		data = new char[length];
		objFile.seekg(0, std::ios::beg);
		objFile.read(data, length);
		objFile.close();
		e->m_BufferSize = (length / (sizeof(float) * 9));
		glGenVertexArrays(1, &e->m_VAO);
		glBindVertexArray(e->m_VAO);
		glGenBuffers(1, &e->m_Buffer);
		glBindBuffer(GL_ARRAY_BUFFER,  e->m_Buffer);
		glBufferData(GL_ARRAY_BUFFER, length, data, GL_STATIC_DRAW);
		glEnableVertexAttribArray(0);
		glEnableVertexAttribArray(1);
		glEnableVertexAttribArray(2);
		glVertexAttribPointer(0, 4, GL_FLOAT, GL_FALSE, sizeof(float) * 9, BUFFER_OFFSET(0));
		glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, sizeof(float) * 9, BUFFER_OFFSET(sizeof(float) * 4));
		glVertexAttribPointer(2, 3, GL_FLOAT, GL_FALSE, sizeof(float) * 9, BUFFER_OFFSET(sizeof(float) * 6));
		glBindVertexArray(NULL);
	}

in this snippet I am loading in the file and sending it to openGL and setting the vbo settings in the VAO. When I run this code data does contain the file so I am not sure why its not rendering.

Thanks for your help and insight in advance:).

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When you examine in a hex editor the file you created on disk, is the data correct?

Did the vertex data get loaded correctly upon examination after the ifstream::read() function returns?

Does glGetError() give any errors?

Do you correctly render geometry that did not come from a file? (I assume so, since you specifically point out an issue with rendering from content from a file)

What does your rendering code look like?

When you examine in a hex editor the file you created on disk, is the data correct?

Did the vertex data get loaded correctly upon examination after the ifstream::read() function returns?

Does glGetError() give any errors?

Do you correctly render geometry that did not come from a file? (I assume so, since you specifically point out an issue with rendering from content from a file)

What does your rendering code look like?

I took the char * data and wrote it to a file and compared the 2 files and they are identical, so I believe that its reading in correctly.

glGetError() returns 0 after every vbo and vao GL call.

I have rendered stuff to the screen so I know my pipeline is somewhat correct.

my render code is :


void renderManager::render() 
{
	SHADER_MANAGER->sendToShader("frustrum", CAMERA->perspectiveMatrix);
	SHADER_MANAGER->sendToShader("view", CAMERA->viewMatrix);
	for (unsigned int i = 0; i < renderingBuffer.size(); i++) 
	{
		SHADER_MANAGER->sendToShader("model", renderingBuffer[i]->PositionMatrix);
		glBindVertexArray(renderingBuffer[i]->m_VAO);
		glDrawArrays(GL_TRIANGLES, 0, renderingBuffer[i]->m_BufferSize);
	}

	glBindVertexArray(NULL);
}

my shaders and program are linked and binded already. In this snippet I am passing my view, projection and model matrix to the shader.

After that I am binding the objects VAO then calling draw.

then unbinding all VAOs.

as for the hex editor would you be able to recommend one I have notePad++ but im not sure if it has a hex editor plugin

thanks for your time

**so I found the hex editor plugin for notePad++ however I selected the file and ran it and it outputted bad allocation..

originally the data was in floats and I put them into a union with a float and a char[4] its a little odd that its corrupted:/

here is a file that im trying to render it is just a small cube that is triangulated


ÉÞMÁÉÞMÁÉÞMA  €?  À>              €?ÉÞMAÉÞMÁÉÞMA  €?   ?              €?ÉÞMÁÉÞMAÉÞMA  €?  À>  €>          €?ÉÞMÁÉÞMAÉÞMA  €?  À>  €>          €?ÉÞMAÉÞMÁÉÞMA  €?   ?              €?ÉÞMAÉÞMAÉÞMA  €?   ?  €>          €?ÉÞMÁÉÞMAÉÞMA  €?  À>  €>      €?    ÉÞMAÉÞMAÉÞMA  €?   ?  €>      €?    ÉÞMÁÉÞMAÉÞMÁ  €?  À>   ?      €?    ÉÞMÁÉÞMAÉÞMÁ  €?  À>   ?      €?    ÉÞMAÉÞMAÉÞMA  €?   ?  €>      €?    ÉÞMAÉÞMAÉÞMÁ  €?   ?   ?      €?    ÉÞMÁÉÞMAÉÞMÁ  €?  À>   ?          €¿ÉÞMAÉÞMAÉÞMÁ  €?   ?   ?          €¿ÉÞMÁÉÞMÁÉÞMÁ  €?  À>  @?          €¿ÉÞMÁÉÞMÁÉÞMÁ  €?  À>  @?          €¿ÉÞMAÉÞMAÉÞMÁ  €?   ?   ?          €¿ÉÞMAÉÞMÁÉÞMÁ  €?   ?  @?          €¿ÉÞMÁÉÞMÁÉÞMÁ  €?  À>  @?      €¿    ÉÞMAÉÞMÁÉÞMÁ  €?   ?  @?      €¿    ÉÞMÁÉÞMÁÉÞMA  €?  À>  €?      €¿    ÉÞMÁÉÞMÁÉÞMA  €?  À>  €?      €¿    ÉÞMAÉÞMÁÉÞMÁ  €?   ?  @?      €¿    ÉÞMAÉÞMÁÉÞMA  €?   ?  €?      €¿    ÉÞMAÉÞMÁÉÞMA  €?   ?      €?        ÉÞMAÉÞMÁÉÞMÁ  €?  `?      €?        ÉÞMAÉÞMAÉÞMA  €?   ?  €>  €?        ÉÞMAÉÞMAÉÞMA  €?   ?  €>  €?        ÉÞMAÉÞMÁÉÞMÁ  €?  `?      €?        ÉÞMAÉÞMAÉÞMÁ  €?  `?  €>  €?        ÉÞMÁÉÞMÁÉÞMÁ  €?   >      €¿        ÉÞMÁÉÞMÁÉÞMA  €?  À>      €¿        ÉÞMÁÉÞMAÉÞMÁ  €?   >  €>  €¿        ÉÞMÁÉÞMAÉÞMÁ  €?   >  €>  €¿        ÉÞMÁÉÞMÁÉÞMA  €?  À>      €¿        ÉÞMÁÉÞMAÉÞMA  €?  À>  €>  €¿ 

so I wrote a little code on the engine to cast it back to float and the data looks perfect:/

heres the code


	for (int i = 0; i < buffer.size() - 3; i += 4) 
		{
	char tempArray[4] = { buffer[i], buffer[i + 1], buffer[i + 2], buffer[i + 3] };
			float f;
			memcpy(&f, &tempArray, sizeof(f));
			packedData.push_back(f);
		}

Assuming the data and buffers are correct, have you checked the active shader is setup correct?

Assuming the data and buffers are correct, have you checked the active shader is setup correct?

The shaders are correct they have a built in error checking system. :/maybe its my drawing I really am at a loss right now.

guys I am such an idiot. I wrote some quick camera class and hacked the view matrix real quick to make it do what I want and I changed a scale value that when multiplied by a translation matrix makes the w or data[15] go right out of wack-.-. I am sorry for wasting peoples time. on the plus note I am not crazy lol I went through so much data and everything was working perfectly.

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